1. Field of the Invention
The present invention relates to a polymer composition excellent in fuel cost-saving properties and a conjugated diene based polymer for producing the polymer composition.
2. Description of the Related Art
In recent years, with an increase in concern about environmental problems, requirements of fuel cost-saving properties on automobiles have been increasing, and a rubber composition used in automobile tires has also been required to be excellent in fuel cost-saving properties. As a rubber composition for automobile tires, a rubber composition containing a conjugated diene based polymer such as polybutadiene or a styrene-butadiene copolymer, and a reinforcing agent is used.
For example, Patent Document 1 suggests a styrene-butadiene copolymer containing many vinyl bonds, and a polymer composition using the copolymer.
[Patent Document 1] JP 01-29802 B1